EFFECT OF EXTRUSION ON FUNCTIONAL COMPONENTS AND IN VITRO BIOACCESSIBILTY OF β-CRYPTOXANTHIN AND ZEAXANTHIN A THESIS SUBMITTED TO THE GRADUATE SCHOOL OF NATURAL AND APPLIED SCIENCES OF MIDDLE EAST TECHNICAL UNIVERSITY BY ÖZGE YEĞİN IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN FOOD ENGINEERING NOVEMBER 2014 i ii Approval of the thesis: EFFECT OF EXTRUSION ON FUNCTIONAL COMPONENTS AND IN VITRO BIOACCESSIBILTY OF β-CRYPTOXANTHIN AND ZEAXANTHIN submitted by ÖZGE YEĞİN in partial fulfillment of the requirements for the degree of Master of Science in Food Engineering Department, Middle East Technical University by, Prof. Dr. Gülbin Dural Ünver Dean, Graduate School of Natural and Applied Sciences _______________ Prof. Dr. Alev Bayındırlı Head of Department, Food Engineering _______________ Assoc. Prof. Dr. İlkay Şensoy Supervisor, Food Engineering Dept., METU _______________ Prof. Dr. Zümrüt Begüm Ögel Co-supervisor, Food Engineering Dept., METU _______________ Examining Committee Members: Asst. Prof. Dr. Yeşim Soyer Food Engineering Dept., METU _______________ Assoc. Prof. Dr. İlkay Şensoy Food Engineering Dept., METU _______________ Asst. Prof. Dr. Mecit Öztop Food Engineering Dept., METU _______________ Asst. Prof. Dr. Aslı İşçi Yakan Food Engineering Dept., Ankara University _______________ Asst. Prof. Dr. Umut Yücel Food Engineering Dept., METU _______________ Date: 12.11.2014 iii I hereby declare that all information in this document has been obtained and presented in accordance with academic rules and ethical conduct. I also declare that, as required by these rules and conduct, I have fully cited and referenced all material and results that are not original to this work. Name, Last name: Özge Yeğin Signature: iv ABSTRACT EFFECT OF EXTRUSION ON FUNCTIONAL COMPONENTS AND IN VITRO BIOACCESSIBILTY OF β-CRYPTOXANTHIN AND ZEAXANTHIN Yeğin, Özge M. S., Department of Food Engineering Supervisor: Assoc. Prof. Dr. İlkay Şensoy Co-supervisor: Prof. Dr. Zümrüt Begüm Ögel November 2014, 110 pages Red pepper pulp was added as a functional ingredient to the extrudates. Effects of extrusion on the functional properties of the red pepper pulp added corn grit extrudates were investigated. Antioxidant activity, total phenolic content, and the amounts of xanthophyll carotenoids in the product, such as β-cryptoxanthin and zeaxanthin, were determined before and after the extrusion process. In vitro v bioaccessibility of these carotenoids from the extrudates and the feed were also investigated. Starch gelatinization (with DSC), pectin, protein, moisture and ash contents were determined for the feed and the product. Two different temperature profile were applied for the barrel zones during extrusion: 80°C, 90°C, 100°C and 130°C (die: 121°C) and 80°C, 105°C, 130°C and 160°C (die: 142°C). Screw speed (225 rpm) and feed flow rate (36 g/min) were kept constant. Feed moisture content was 25 ± 0.5%. Total phenolic content of the samples were found to decrease about 41.72% and 47.68% whereas antioxidant activity of the samples were found to decrease about 28.92% and 22.89% after 130°C and 160°C last zone temperature extrusion process, respectively. No gelatinization peak was observed on DSC thermograms after extrusion whereas a peak was observed before extrusion. High performance liquid chromatography (HPLC) analysis showed a decrease in β-cryptoxanthin content about 17.53% and 28.87% whereas a reduction was observed in zeaxanthin content about 49.83% and 40.07% after 130°C and 160°C last zone temperature extrusion process, respectively. There was not statistically significant difference between in vitro bioaccessibility of β-cryptoxanthin and zeaxanthin of feed and extrudates. The results suggest that red pepper pulp can be added as a functional ingredient to develop new functional extruded food products. Keywords: Extrusion, red pepper, in vitro bioaccessibility, β-cryptoxanthin, zeaxanthin vi ÖZ EKSTRÜZYONUN FONKSİYONEL BİLEŞENLER VE β-KRİPTOZANTİN VE ZEAKSANTİNİN IN VITRO BİYOERİŞİLEBİLİRLİĞİ ÜZERİNE ETKİSİ Yeğin, Özge Yüksek Lisans, Gıda Mühendisliği Bölümü Tez Yöneticisi: Doç. Dr. İlkay Şensoy Ortak Tez Yöneticisi: Prof. Dr. Zümrüt Begüm Ögel Kasım 2014, 110 sayfa Kırmızı biber posası ekstrüde ürünlere fonksiyonel bileşen olarak eklenmiştir. Ekstrüzyonun mısır irmiğine kırmızı biber posası eklenmiş ekstrüde ürünlerin fonksiyonel bileşenleri üzerine etkisi incelenmiştir. Üründeki antioksidan aktivite, toplam fenol miktarı ve ksantofil karotenoidler olan β-kriptozantin ve zeaksantin miktarları ekstrüzyon işlemi öncesi ve sonrası araştırılmıştır. Besleme ve ekstrüde vii ürünlerde bu karotenoidlerin in vitro biyoerişilebilirliği de incelenmiştir. Besleme ve ürünlerin nişasta jelatinizasyonu (DSC ile), pektin, protein, nem ve kül miktarları ölçülmüştür. Ekstrüzyon işlemi sırasında silindir bölgelerinde iki farklı sıcaklık seti uygulanmıştır: 80°C, 90°C, 100°C ve 130°C (kalıp: 121°C) ve 80°C, 105°C, 130°C ve 160°C (kalıp: 142°C). Vida hızı (225 dev/dk) ve besleme hızı (36 gr/dk) olarak sabit tutulmuştur. Beslemenin nem miktarı %25 ± 0.5 dir. 130°C ve 160°C son bölüm sıcaklığında ekstrüzyon sonrası, örneklerin toplam fenol miktarı sırasıyla %41.72 ve %47.68 azaldığı tespit edilirken örneklerin antioksidan aktivitelerinin %28.92 ve %22.89 azaldığı gözlemlenmiştir. Ekstrüzyon işleminden sonra DSC termogramlarında jelatinizasyon piki gözlenmezken ekstrüzyon işlemi öncesi pik görülmüştür. Yüksek performanslı sıvı kromatografisi (HPLC) analizi 130°C ve 160°C son bölüm sıcaklığında ekstrüzyon sonrası β-kriptozantin miktarında sırasıyla %17.53 ve %28.87 azalma gösterirken zeaksantin miktarında %49.83 ve %40.07 azalma göstermiştir. Besleme ve ekstrüde ürünlerin β- kriptozantin ve zeaksantin in vitro biyoerişilebilirliği arasında istatistiksel olarak anlamlı bir fark yoktur. Sonuçlara göre fonksiyonel özelliklere sahip yeni ekstrüde gıda ürünleri üretebilmek için kırmızı biber posası fonksiyonel katkı maddesi olarak eklenebilir. Anahtar Kelimeler: Ekstrüzyon, kırmızı biber, in vitro biyoerişebilirlik, β- kriptozantin, zeaksantin viii Dedicated to my family ix ACKNOWLEDGEMENTS Without encouragement of the people that I would like to mention below, this thesis cannot be completed. I would like to express my sincere gratitude to my supervisor Assoc. Prof. Dr. İlkay Şensoy for her continuous support, guidance, valuable suggestions and cooperation which brought this study to a successful end. I am also thankful for her patience and understanding at all stages of this study. I would also thank to my co-supervisor Prof. Dr. Zümrüt Begüm Ögel for her assistive suggestions. I am grateful to Prof. Dr. Gülüm Şumnu, Dr. Zinet Aytanga Ökmen and Dr. Betül Söyler for their laboratory support and advices. In addition, I would like to express my sincere gratitude to members of my examining committee members. I would like to thank to Prof. Dr. Sibel Karakaya in Food Engineering Department of Ege University, İzmir, Turkey to let me to use her nutrition laboratory during in vitro analyses and her suggestions. I would also like to thank to graduate students Gülay Öncü, Nazlı Korkmaz, Aslı Kancabaş Kılınç, Hülya İlyasoğlu and Nilüfer Girgin in Food Engineering Department of Ege University for their help in the laboratory and their hospitality. It is my pleasure to express my sincere appreciations to Dr. Cem Baltacıoğlu and Dr. Hande Baltacıoğlu for their advice and helps anytime I needed. It is my honour to thank Prof. Dr. Levent Bayındırlı to make me like food engineering and his courses, and his precious advices. I also would like to express my thanks to my best friends Raziye Başak Özden, Özlem Ergin and Ayça Aydoğdu not only for their support and encouragement but also for their be with me since the first year of the university. x I would like to thank my friends and lab mates Nuran Nisa Ilgaz, Bade Tonyalı and Çağla Çaltinoğlu for being a good friend, their support and help during my study. I offer thanks to The Scientific and Technological Council of Turkey (TÜBİTAK 110 O 792) for financial support during my thesis. Finally, I would like to express my special gratitude to my husband Halil Güngör Yoldaş for his precious love, encouragement and support in my life. I am profoundly indebted to my family; my mother Nermin Yeğin, my father Şaban Yeğin, and my sister Özgül Yeğin Mülazımoğlu and her husband Emre Mülazımoğlu and my lovely nephew Ece Mülazımoğlu for their love, help and tireless devotion throughout my life who provided me everything in receiving the M.S. degree. Words are not sufficient to express my gratitude and love to them. I dedicate this work to my family. xi TABLE OF CONTENTS ABSTRACT ................................................................................................................. v ÖZ ............................................................................................................................... vii ACKNOWLEDGEMENTS ......................................................................................... x TABLE OF CONTENTS ........................................................................................... xii LIST OF TABLES .................................................................................................... xiv LIST OF FIGURES .................................................................................................... xv CHAPTERS ................................................................................................................. 1 1. INTRODUCTION